Filariae and Leishmania endemicity areas overlap in many regions of Mali. Both represent important public health problem due to their distribufion, prevalence, and associated clinical features. These 2 neglected parasific tropical diseases are vector borne with mosquitoes and phlebotomine sand flies as respective vectors for filariasis and leishmaniasis. In co endemic areas, the interacfion between filariae, sand fly saliva and Leishmania and how they modulate host immunity and whether such interacfions have an effect on disease outcome is of great importance, not well understood, and the aim of this project. The aim of this study is first to address whether salivary proteins of a sand fly are capable of altering the funcfion of APC (anfigen presenfing cells), particularly the macrophages, and second how patent filariasis may alter the immune response of the human host to these proteins. The study will be done in villages of Mopfi and Segou Districts of Mali. An immune chromatographic card test (ICT) for circulafing filarial antigen using whole blood will be performed in these areas. For exposure to salivary proteins, the sera of both mf- and mf+ individuals will be then screened by Elisa and Western blot. For cutaneous leishmaniasis (CL), a leishmanin skin test (LST) will be conducted to identify a cohort of individuals that are LST negative at the outset of the study. This study will have a significant impact on the immune response of humans to Leishmania infecfions as a result of an altered immune response to salivary proteins. All the data generated will be novel and will contribute tremendously to the scientific community and our knowledge of the complexity of the immune response. Furthermore, establishing the effects of salivary proteins on human Mij) (which have not been addressed in the past) may lead to the discovery of molecules with adjuvant-like property that can be important in designing potential vaccines. RELEVANCE (See instructions): This study has a public health significance as it will contribute to understand how the immune response can be affected in presence of 2 parasites. The study will provide informafion that will guide vaccine and/or adjuvant development to fight these two endemic diseases in poor countries.